This thesis examines the change of price of the process of initial public offerings (IPO).When companies apply for IPO, investors will expect that information of the company will become more transparent and make information asymmetry disappear, and then it will improve the liquidity of stocks. Therefore, there is significant positive excess return. We find that there is significant positive excess return on the process. In addition, we also examines the effect of the capital gains tax on securities transactions. We find that the underpricing of IPOs decline after the implementation of the tax.